Fuel antiknock



41min.

Sha i-Mk1 United States atent FUEL ANTIKNOCK No Drawing. ApplicationAugust 13, 1953,

Serial No. 374,160

8 Claims. (Cl. 44-69) This invention relates to the improvement oforganolead material, and in particular to adjuvants for tetraethylleadand tetraethyllead-containing compositions.

organolead compounds such as tetraphenyllead, tetramethyllead,tetraethyllead, dimethyldiethyllead, and the like have long been knownas antiknock agents for fuel for spark ignition type internal combustionengines. Of such materials, however, only tetraethyllead has attainedcommercial success because of its efficacious attributes. Likewise, ithas long been known that the effective utilization of such antiknockagents is enhanced by providing antiknock fluids which consist oforganic halogen compounds in admixture with an organolead compound.

Organolead compounds sufler one disadvantage, particularly duringstorage, handling, and blending operations, namely, their inherentinstability. Thus, tetraethyllead and related compounds are susceptibleof deterioration which is largely dependent upon the nature of theenvironment. For example, it has been found that organolead antiknockagents and antiknock fluids containing the same, when in contact withcertain metals, such as copper and copper-containing alloys, tend todeteriorate, even in a reducing atmosphere. Such deterioraticn ispostulated to result from an adverse cata lytic activity efiibited bysuch metals. In other Words, it is generally believed that copper andlike metals act as self-perpetuating decomposition accelerators. Anothercondition enhancing the deterioration of such antiknock agents iscontact with air. It is generally believed that atmosphericconstituents, notably oxygen and ozone, tend to oxidize one or more ofthe lead-to-carbon bonds with the formation of insoluble decompositionproducts. Under these conditions there contemporaneously occurs a colorchange in the dyestufl normally present in antiknock fluids such thatthe visual identification of the product frequently becomes dihicult, ifnot impossible. Organolead antiknock agents are likewise decomposed onexposure to strong light, particularly sunlight. In this case thedecomposition is attributed to the catalytic decomposition of theorganolead compounds by ultra-violet light. It is apparent, therefore,that the exposure of tetraethyllead and tetraethyllead-containingcompositions to any or all of the above environments results in a number:of operational difliculties, including loss of antiknock effectiveness,the formation of sludge and other types of sediment, and the like.

When organolead-containing compositions are utilized in internalcombustion engines, other difliculties are frequently encountered. Forexample, in spite of the high degree of efficiency of the normalscavenger complement in antiknock fluids, the accumulation of enginedeposits in the engine cannot be entirely prevented. Such deposition isparticularly prevalent when spark ignition engines are operated underconditions of low speed and light load, such as encountered inmetropolitan driving conditions. As a result of notable improvements infuel antiknock quality which have been made in recent years, suchdeposits present but a few minor problems in low Patented June 4, 1957compression engines. However, because of the trend in the automotiveindustry of utilizing high compression engines in passenger cars andtrucks, the accumulation of deposits results in a number of relativelyserious problems, including increased detonation, deposit-inducedautoignition or wild ping, spark plug fouling, reduction in exhaustvalve life, and the like.

Of the problems previously enumerated, those of wild ping, spark plugfouling, and reduced exhaust valve life are of considerable concern tothe automotive industry. This results from the fact that each time thelead concentration in the fuel is raised to coincide with increases incompression ratio to eliminate detonation, the magnitude of one or moreof these problems generally increases. As a result, there is a paramountneed existing for a new and improved method for altering the physicaland chemical characteristics of deposits and for modifying thecombustion process such that the well-known detrimental eflects of thepreviously described deposit-induced engine phenomena can be markedlysuppressed or be eliminated.

It is, therefore, an object of this invention to provide adjuvants fororganolead compounds. It is likewise an object of this invention toprovide means of improving compositions such as antiknock fluids andfuels which contain organolead antiknock agents. Similarly, theprovision of improved organolead compositions is another object of thisinvention. A particular object of this invention is to provide improvedtetraethyllead-containing fuels, especially those for use in sparkignition type internal combustion engines. In addition, an object ofthis invention is to provide methods of improving antiknock fluids suchthat during compounding, storage and blending operations such materialsare stabilized against the adverse effects of deteriorativeenvironments. An additional object of the instant invention is toprovide means of obviating deposit-induced phenomena of the characterdescribed hereinbefore. Other important objects of this invention willbe apparent from the discussion hereinafter.

It has now been found that the above and other objects of this inventionare attained by providing compositions of matter adapted for use asadditives to fuel for sparkfired internal combustion engines comprisingan organo lead antiknock agent and, in quantity sufiicient to stabilizeor improve said agent, a metallic derivative of a product obtained byreaction between a phosphorus sulfide and an active hydrogen-containingamine. Therefore, the adjuvants of this invention are formed from thereaction product between such compounds as phosphorus pentasulflde(P285), phosphorus heptasulfide (P487), or the like and a primary orsecondary monoor polyamine; that is, a compound which'contains at leastone hydrogen atom attached to the nitrogen atom. For the sake ofconciseness, such materials are termed hereinafter as the organicreactants.

It will be apparent that the organolead adjuvants of this invention aremost readily prepared in two steps. The first step consists of preparinga product of a phosphorus sulfide and organic reactant of the typedescribed hereinbefore. Depending upon the nature of the materialsemployed as Well as the reaction conditions, the product of thisreaction can be used in its entirety for the preparation of my metallicderivatives, or it can be subjected to intermediate treatment, as willbecome apparent from the discussion hereinafter. The second step in thepreparation of my adjuvants consists of reacting a salt of the desiredmetal with the above intermediate material.

The organic reactant used to prepare the reaction products used asintermediates in the preparation of my adjuvants is an activehydrogen-containing aliphatic, alicyclic, aromatic or heterocyclicprimary or secondary amine. Typical aliphatic amines include suchsubstances as methyl amine, ethyl amine, propyl amine, isopropyl amine,and likewise the various straight and branched chain alkyl aminesexemplified by the several butyl, amyl, hexyl, heptyl, octyl, and thelike amines up to and including about triacontyl. Additional examples ofthe aliphatic amines which can be employed in preparing my adjuvantintermediates include di-isopropyl amine, methylethyl amine, di-butylamine, di-undecyl amine, dioctadecyl amine, ethenyl amine, di-butenylamine, benzyl amine, N-methylbenzyl amine, and like substances. Ingeneral, the primary and secondary aliphatic amines used to prepare myadjuvant intermediates should contain from 1 to about 30 carbon atomsalthough in some instances benefits are to be derived by employingsomewhat higher molecular weight amines.

The alicyclic active hydrogen-containing amines which can be used toprepare my adjuvant intermediates are exemplified by cyclohexyl amine,dicyclohexyl amine, butylcyclohexyl amine, cyclchexenyl amine, rosinamine, and the like. As in the case of the aliphatic amines my adjuvantintermediates are preferably prepared from alicyclic amines containingup to about 30 carbon atoms.

The aromatic amines which can be used to prepare the organoleadadjuvants of the instant invention are substances where in the aminogroup, which can be substituted with one additional hydrocarbon radical,is directly attached to an aromatic nucleus such as that of benzene,naphthalene, diphenyl anthracene, and the like. Representative membersof the primary aromatic amines which can be used to prepare by adjuvantintermediates include aniline, Z-methyl aniline, 3-methyl aniline,4-methyl aniline, 2,3-diethyl aniline, 3,4-dibutyl aniline, 2,6-dihexylaniline, 2-methyl-4-isopropyl aniline, 2,5-dicetyl aniline, a-naphthylamine, ,B-naphthyl amine, a-anthryl amine, fl-anthryl amine, 'y-anthrylamine, and the like. The secondary aromatic amines which can likewise beemployed in preparing my adjuvant intermediates are com pounds whereinone of the hydrogen atoms of the amino group is replaced with an organicradical. Such substances are typified by N-methyl aniline, N-propylaniline, N-t-butyl aniline, N-phenyl aniline, N-cyclohexyl aniline,N-methyl-fi-naphthyl amine, N-methyl-2-methyl aniline,N-cyclohexyl-2-4-dimethyl aniline, and the like.

As indicated hereinbefore recourse can be made to polyamines in thepreparation of the intermediates for the organolead adjuvants of thepresent invention. That is to say, suitable adjuvant intermediates canbe prepared by utilizing as a prime reactant such diamines as ethylenediamine, propylene diamine, butylene diamine, hexylene diamine, and thelike as well as analogous materials in which one of the hydrogen atomson one or more of the amino groups is replaced by an organic radical.Likewise, recourse can be made to aromatic diamines such as ortho meta-,and para-phenylenediamine, and similarly analogous aromatic diamines inwhich at least one hydrogen atom is replaced with an aliphatic,alicyclic, or aromatic radical. Furthermore, suitable adjuvantintermediates can be prepared from aliphatic, alicyclic, aromatic, orheterocyclic primary or secondary hi, or tetra-amino compounds. In otherwords, as will become apparent to one skilled in the art, the primecriterion utilized to determine the nature of a suitable amine for usein accomplishing the objects of this invention is the fact that suchamines can contain any feasible number of amino functions so long as atleast one of them contains a hydrogen atom directly attached to thenitrogen atom. Generally speaking the amines utilized to prepare myadjuvants should contain from 1 to about 30 carbon atoms although thisis contingent upon the particular type of amine in question.

7 While the organic reactants described thus far generally representsingle chemical entities, it is frequently preferred to utilize as thereactant mixtures of the various materials, especially mixtures whichare readily available as articles of commerce. For example, typical mixf2,?94323 7 e a r tures of suitable active hydrogen-containing amines arerepresented by nitrogen-containing naphthenic bases derived frompetroleum, and nitrogen-containing coal tar bases and similarcommercially available mixtures. It will thus be apparent that theactive hydrogen-containing amine used to prepare my adjuvantintermediates can be a mixture of different amines of difierentmolecular weight and degrees of substitution and containing unsaturatedor saturated radicals. Furthermore, the presence of minor proportions oftertiary amines, hydrazo compounds and the like can be tolerated.Likewise, it is often advantageous to employ mixtures of two or moresubstantially pure amines of the character described hereinbefore so asto ultimately prepare tailor-made adjuvants for accomplishing theobjectives of this invention. Other readily available mixtures of activehydrogencontaining amines will be apparent to those skilled in the art.

The phosphorus sulfide, the other prime reactant utilized in thepreparation of my intermediates, is preferably a reactive compound suchas P255 (P4810) and P487. It is possible, however, to use certain of theother reported phosphorus sulfides under the proper reaction conditions.Furthermore, another related reagent which can be successfully utilizedin preparing the intermediates for my adjuvants is thiophosphorylchloride, PSCls. It will likewise be apparent that under suitableconditions the various sulfides of arsenic or antimony can be similarlyemployed in forming intermediates for use in the present invention.

The intermediate products for the preparation of the adjuvants of thisinvention are readily prepared, the reaction generally requiring onlythe addition of a reactive phosphorus sulfide to the organic reactantand heating the mixture at a temperature at which the reaction takesplace as evidenced by the release of hydrogen sulfide until the reactionis substantially complete. The temperature of the reaction is largelydependent upon the nature of the individual reactants, although,generally speaking, temperatures in the order of about to 500 F. aresatisfactory. In preparing some of the intermediates for my adjuvantsadvantages are to be obtained by conducting the reaction undersuperatmospheric pressure which can be readily obtained by conductingthe reaction in a closed vessel, thereby taking advantage of thepressure resulting from the hydrogen sulfide so formed.

The nature of the reaction products is somewhat contingent upon theratio of the reactants. That is to say, variations in the character ofthe intermediates are achieved by utilizing difierent organicreactant-to-phos phorus sulfide mole ratios within the range from about0.5 to l and about 10 to l.

The reaction products can be made in the presence of a diluent, ifdesired, which may or may not be subsequently removed. Such diluents areillustrated by such substances as kerosene, straight run andcatalytically cracked hydrocarbons of the diesel fuel boiling range, andthe like.

The reaction products used to form my adjuvants defy precise chemicaldefinition. For example, although it is genermly believed that thereaction products contain a substantial proportion of materialcontaining phosphorus-to-sulfur bonds, the true nature of the reactionis obscured by a number of competing factors. Gn the one hand, the ratioof the reactants determines to some extent the character of theintermediates as indicated hereinbefore. Furthermore, it is notinconceivable that the temperature at which the reaction is conductedwill influence the amount and character of chemical cleavage, which isundoubtedly inherent in such reactions. Likewise, it will be apparentthat the specific phosphorus sul fide employed will also haveconsiderable bearing upon the nature of my intermediates. Nevertheless,there is considerable evidence attesting to the fact that the activehydrogen possessed by my prime organic reactants is coupled with sulfuratoms from thephosphorus sulfide such that there is a release ofhydrogen sulfide and the provision of a complex molecular reaction mass.Summing up this point, therefore, it is in praesenti impossible toadequately define the nature of the intermediates because of the factthat the reaction mechanism is highly obscured by such factors as theoperation of the law of mass action, reaction kinetics, steiic factors,as Well as consideration of the nature of the prime reactants employed.It may well be that with certain pure starting materials and withcarefully controlled reaction conditions and concentrations,substantially pure reaction products are obtainable. However, anadvantage inherent in this invention is the fact that it is notnecessary to. prepare substantially pure materials and further that itis generally preferred to utilize the reaction product in its entiretyas an intermediate for the preparation of my adjuvants.

As indicated hereinbefore the intermediate reaction product can be useddirectly for the formation of my adjuvants or it can be subjected to anintervening treatment. Such treatment consists of centrifugation orfiltration to remove any by-product, sludge, or other insoluble materialwhich under certain circumstances may be formed. Likewise, any excess ofvolatile reactant or a volatile diluent, if used, can be removed bydistillation. Furthermore, if desired, the intermediate product can beextracted with a suitable solvent such as liquid propane or isopropanol,or can be contacted with an adsorbent such as activated charcoal, silicagel, activated clay or the like.

To prepare my organolead adjuvants the above-described intermediateproduct is reacted with a suitable salt of the desired metal. Forexample, the reaction intermediates can be treated with an oxide,hydroxide, carbonate, or the like of the metal in question. It will beapparent, therefore, that a wide variety of metallic elements can beintroduced into the intermediate products thereby forming a multitude oforganolead adjuvants for use in accordance with the present invention.However, generally speaking, a preferred embodiment of the instantinvention consists of forming and hence utilizing reaction productscontaining an alkali metal such as lithium, sodium, potassium and thelike. An additional preferred embodiment of this invention resides inthe utilization of alkaline earth metal containing reaction products asorganolead adjuvants. Thus, by reacting the product obtained by reactionbetween a phosphorus sulfide and an organic reactant as above-describedwith a suitable salt of such metals as magnesium, barium, calcium,strontium, and the like efiicacious adjuvants of this invention areformed. It will be apparent, however, that other metallic elements canbe used to form suitable adjuvants. For example, aluminum, arsenic andother metals higher in the electromotive series form highly desirableadditives for use in accomplishing the objects of this invention. Theamount of the metallic salt used in preparing my adjuvants can besumcient to neutralize all or part of the acidity of the intermediatereaction product. The reaction itself is preferably carried out at anelevated temperature in the range of about 180 to 350 F. in order tocomplete the neutralization.

The particular conditions employed are naturally contingent upon thenature of the materials in question. By way of example, one generalmethod which can be used in forming my adjuvants is to conduct thereaction in the presence of a suitable diluent such as any of thetypical hydrocarbon solvents. Another modification used in preparing myadjuvants is to conduct the reaction at superatmospheric pressure. Thisis found to be particularly efiicacious in the preparation of metallicadjuvants of this invention formed from metals, the bases of which arerelatively weak. Such is the case with aluminum. On the other hand, theutilization of higher pressures is frequently unnecessary particularlywhen 3 the metallic element being introduced into my organoleadadjuvants is capable of forming strong bases as in the case of thealkali metals.

Once the second step of the reaction has been completed the reactionproduct can be used intoto as an organolead adjuvant or it can besubjected to conventional treatments of the type described'hereinbefore. Thus, recourse can be made to such steps as solventextraction, distillation, filtration, centrifugation, and the like.

While the preparation of my adjuvants has been described in terms ofatwo-step process, it will be appreciated that under certaincircumstances, a one-step process can be used. That is to say,with manyof the prime reactants within the purview of this invention my adjuvantscan be prepared by inter-mixing suitable quantities of a reactivephosphorus sulfide, an organic reactant and a metallic salt, with orwithout a diluent and subjecting this mixture to thermal treatment untilthe reaction is substantially complete. Further details regarding thismethod of preparing my adjuvants will be a apparent to one skilled inthe art.

The organolead antiknock agent utilized in the com.- positions of matterof the present inven ion consists of an organolead compound in whichlead is directly bonded to carbon atoms. Such compounds are exemplifiedby the lead aryls, such as tetraphenyllead, and the lead alkyls, such astetramethyllead, tetraethyllead, tetrapropyllead, tetrabntyllead,dimethyldiethyllead, methyltriethyllead, and the like, as well asmixtures of such compounds. Eecause of the generally superiorcharcteristics of tetraethyilead and the ready accessibility thereof asan article of commerce, it constitutes a preferred embodiment of theorganoleadantiknock agent utilized in acordance with the instantinvention.

With the various compositions within the scope of this invention theproportion of the reaction product utilized in conjunction with anorganolead compound is such that there is a total of from between about0.01 to about 0.80 theory of phosphorus. In this regard, a theory ofphosphorus is defined as the amount of phosphorus theoretically requiredto react with the lead to form lead orthophosphate, which quantity istwo atoms of phosphorus per three atoms of lead. However, generallyspeaking, it is sufficient to employ an amount of an organolead adjuvantof this invention such that there is an amount of phosphorus betweenabout 0.05 and about 0.5 theory, with the best overall results usuallybeing obtained with amounts of about 0.1 to about 0.2 theory ofphosphorus, the last mentioned concentrations constituting a preferredembodiment.

Regarding many of the problems frequently associated with high octanequality fuel, an anomalous situation obtains. On one hand, an effectiveadjuvant for organolead compounds should possess stability againstdeterioration in common environments, compatibility with the chemicalentities with which it comes in contact, and volatility so as to possessthe characteristic frequently referred to as engine inductibility. Onthe other hand, the mere selection .of a phosphorus compound to acquirethe optimum characteristics enumerated above does not necessarily assurethe effectiveness of the compound in combatting such phenomena as sparkplug fouling, wild ping, and the like. It is entirely probable that someempirical relationship between physical properties and effectiveness inthe obviation of such problems exists, but as yet the state of the artdoes not contain a satisfactory relationship of this type. However, thephosphorus materials within the purview of this invention, for the mostpart, possess the requisite physical properties adapting them for use asorganolead adjuvants and at the same time are effective in obviatingengine problems of the type described hereinbefore.

It will be apparent that there exists a number of variations inemploying the adjuvants of this invention. For example, afacet of thisinvention involves the provision of a mixture of an organolead antiknockagent-such as a leadlalkyl and a metal-containing reaction product usedas'an adjuvant in accordance with the present invention. In such casethe resulting composition can be blended with hydrocarbon fuel of thegasoline boiling range to provide an improved fuel composition whichunder certain circumstances does not require the utilization of organichalogen-containing material as a scavenger. It is believed that underthese conditions the presence of a quantity of-phosphorus and sulfur asabove-described and chemically bonded in accordance with therequirements of the adjuvants of this invention contributes sufiicientscavenging'action such that the amount and character of deposition inthe engine are suitably controlled, notwithstanding the fact that leadphosphates generally have high melting points. Likewise, in thisembodiment of the instant invention the general storage characteristicsof organolead compounds are frequently enhanced.

Of perhaps more practical importance is a second variant of thisinvention, namely, the utilization of the aforesaid metal-containingreaction products in organolead-containing antiknock fluids. It is wellknown in the art that the most convenient means of marketing andblending organolead antiknock agents is in the form of an antiknockfluid which usually contains, in addition to the lead compound, one ormore organic bromine and/ or chlorine compounds and an organic dye foridentification purposes. On occasion, such antiknock'fluids likewise maycontain minor proportions of diluents, antioxidants, metal deactivators,and the like. In line with the foregoing, therefore, a preferredembodiment of this invention involves providing improved antiknockfluidscontaining the above-described metal-containing reaction products. Suchimproved antiknock fluids generally do not require the presence of asolubilizing agent or a stabilizer since the phosphorus compound itselfis generally sufiiciently miscible with the constituents of theantiknock fluid and imparts thereto a degree of stabilization. However,under some conditions additional benefits are to be derived by employingin the improved antiknock fluids of this invention the necessaryquantities of such materials.

Still another variant of the present invention consists of providingimproved fuel compositions. These normally consist of hydrocarbons ofthe gasoline boiling range containing a minor proportion'of theaforesaid antiknock fluids of the present invention. It will beappreciatedthat the quantity of the antiknock fluid of the presentinvention utilized in my improved fuel compositions is primarilycontingent upon the use for which the gasoline is intended. That is tosay, when the fuel is intended for use in automotive engines such aspassenger cars, trucks, busses, and the like an amount of any of myimproved antiknock fluids equivalent to a lead content in the gasolineof from between about 0.53 and about 3.17 grams of lead per gallon issatisfactory. Thus, in the embodiments of this invention wherein Iemploy tetraethyllead as an anti knock agent, such concentrations areequivalent to from between about 0.5 and about 3 milliliters of thecompound per gallon. With the advent of the more recent high compressionratio internal combustion engines, however, it is becoming increasinglyapparent that benefits'are to be derived by employing somewhat greaterconcentrations of the .organolead material inautomotive gasoline. Onthis basis, therefore, automotive fuels containing up to about 4.75grams of lead per gallon are contemplated. In contrast, when theimproved antiknock fluidsof the present invention are utilized in fuelfor aviation engines,

somewhat higher concentrations are employed. Gen

erally speaking, amounts of lead up to about 6.34 grams of lead 'pergallon can be utilized, although somewhat lesser quantities arepresently in vogue. In other words, in the tetraethyllead-containingembodiments of this in vention there can be present up to about 6milliliters of tetraethyllead per gallon as an improved antiknock fluidof my invention. Concentrations above these limits can be employed inbothmotor and aviation fuels, practical considerations being the primecriterion for establishing the upper concentration limit. As indicatedhereinabove, in all of the compositions of the present invention theamount of phosphorus is fixed within the limits abovedescribed. Thus, inthe preferred fuel embodiments of my invention there is present anamount of phosphorus as a metal-containing reaction product such thatthere is from about 0.1 to 0.2 theory of phosphorus. In preparing theimproved fuel compositions of this invention it is usually necessaryonly to add the requisite quantity of the improved fluid to the fuel,and by means of stirring, shaking, or other means of physical agitation,homogeneous fuel compositions are provided. Although the simplest meansof preparing such fuels is to blend therewith the necessary quantity ofan improved antiknock fluid of this invention, it is possible to add aconventional antiknock fluid to the fuel and subsequently blendtherewith the necessary quantity of a metallic derivative of a productobtained by reaction between a phosphorus sulfide and an activehydrogen-containing amine. In addition to re versing this order ofaddition of conventional antiknock fluids and metal-containing reactionproducts, another variant within the purview of this invention is toblend with the fuel each of the individual constituents of my antiknockfluids separately.

The following specific examples wherein all parts and percentages are byweight are illustrative of the methods which can be employed inpreparing the organolead adjuvants of this invention.

Example I To an all-glass reaction vessel equipped with a stirrer isadded 780 parts of a commercially available mixture of amines consistingof about 25 percent of dihexadecyl amine and percent of dioctadecylamine. Then is added 333 parts of P285 and 2340 parts of 30 V. I. SAE-ZOoil as a diluent. The entire mixture is then heated to a temperature of500 F. with stirring for a eriod of four hours. The reaction product isthen fil tered while hot so as to remove the small amount of undesirableproducts which have formed. To parts of the above reaction product isadded 12 parts of barium hydroxide (Ba(OH)z-8H2O). This mixture is thenheated at a temperature of 180 F. for two hours after which time thetemperature is raised to 250 F. where it is maintained for an additionaltwo hours while pass ing air through the mixture. Small amounts of solidmaterial are removed by filtration preferably while the mixture is hot.

Example 11 To a suitable glass reaction vessel is added 940 parts ofdodecyl amine and 280 parts of P285. The reaction mixture is heated at260 C. for a period of four hours and then cooled to room temperature.The reaction mixture is then diluted with 680 parts of toluene andfiltered. To 100 parts of the filtrate is added 8 parts of lithiumhydroxide (Li(OH)-II2O) and 4 parts of water. This mixture is thenheated under a pressure of pounds per square inch for two hours at atemperature of 250 F. On completion of the reaction the product iscentrifuged so as to separate excess water and stripped with air at 212F. for the purpose of drying the product. It is preferable to filter theend product so as to remove minor amounts of solid material.

The reactants and reaction conditions described in'the previous specificexamples are merely illustrative. For example, by utilizing the aboveand'similar reaction conditions it is possible to prepare suitableadjuvants of this invention by reacting a' phosphorus sulfide such asP285, P437 and the like with such organic reactants as diamyl amine,rosin amine, tall oil amine, methyl amine, amyl amine, ethyl amine,tetraethylene pentamine and, in turn, the product with oxides orhydroxides of lithium, sodium,

' described engine test procedure.

potassium, calcium, magnesium, barium, zinc and like metals. i Toillustrate the effectiveness of the improved antiknock fluids of thepresent invention, consideration can be given to the problem of sparkplug fouling. In order to do this, recourse can be made to the followinggeneral test procedure utilizing a standard modern V-8 engine equippedwith overhead valves having a 3% bore, a 3 stroke, a 303.7 cubic inchdisplacement, and a compression ratio of 7.25 to One equipped withcommercially available spark plugs. In order to establish a base linethis engine is operated in conjunction with an engine dynamometer on astandard commercial fuel containing 3 milliliters of tetraethyllead pergallon as conventional antiknock fluid containing 0.5 theory of bromineas ethylene dibromide and 1.0 theory of chlorine as ethylene dichloride.The engine is operated under a durability schedule used for spark plugdeposit accumulation patterned after road conditions experienced in citydriving which are known to producespark plug fouling of the greatestmagnitude. Such operation is substantially continuous until a number ofspark plug failures is detected thereby establishing a quantitativemeasure of the degree of spark plug fouling which can be expressed inaverage hours to plug failure. The engine is then freed from depositsand equipped with new spark plugs. The same procedure is repeated usingthe same fuel base stock to which is added an improved antiknock fluidof the present invention.

By way of example, when 300 gallons of a petroleum hydrocarbon fuelavailable as an article of commerce is -treated with 900 milliliters oftetraethyllead in a fluid containing tetraethyllead, 0.5 theory ofbromine as ethylene dibromide and 1.0 theory 'of chlorine as ethylenedijchloride, a suitable fuel is prepared for establishing a base line ofhours'to spark plug failure. When the standard V-8 engine describedhereinbefore is then operated on this homogeneous fuel composition, itis found that in an average time of about 34 hours 3 spark plug failureshave occurred.

In contrast, when a suitable quantity of the same fuel base stock istreated with an improved antiknock fluid of the present invention,greatly enhanced spark plug life is obtained. For example, when 1000gallons of the same fuel base stock is treated with .3 liters oftetraethyllead as a fluid comprising 0.5 theory of bromine as ethylenedibromide, 1.0 theory of chlorine as ethylene dichloride, and 0.2 theoryof phosphorus as the lithium salt of the reaction product between rosinamine and P285, an improved fuel of the present invention results. Uponintimately mixing the aforementioned components the homogeneous fuelcomposition containing 3.0 milliliters of tetraethyllead per gallon issuitable for use in the above- It is found that a substantialimprovement in spark plug performance as evidenced by the greater periodof continuous engine operation resultsfrom the utilization of such animproved fuel of the present invention. That is to say, the averagehours to three spark plug failures is substantially in excess of thebase line figure of 34 hours.

When such adjuvants as the lithium salt of the reaction product betweenP457 and octadecyl amine, the potassium salt of the reaction productbetween PSCls and diamyl amine and the like are utilized in accordancewith the present invention comparable effectiveness regardingminimization of spark plug fouling is obtained. Without desiring to bebound by the following explanation regarding the enhanced effectivenessof the adjuvants of this invention, a tenable explanation apparentlyinvolves a proper balance between physical properties such as stability,volatility, solubility, compatibility and the like and the energyrelationships or ease of decomposition which may attribute to theover-all effectiveness of my adjuvants by facilitating decomposition atthe proper instant in the engine cycle.

To still further illustrate the enhanced effectiveness 10 of theorganolead-containing compositions of the present inventionconsideration can be given to the problem of wild ping. To demonstratethe effectiveness of my compositions in this regard, I can subject botha hydrocarbon fuel treated in accordance with this invention and anotherportion of the same hydrocarbon fuel treated with a conventionalantiknock mixture to a test procedure involving the use of asingle-cylinder CFR knock test engine equipped with an L-head cylinderand a wild ping counter which records the total number of wild pingswhich occur during the test periods. Such apparatus includes an extraspark plug used as an ionization gap which is installed in a secondopening in the combustion chamber. A mechanical breaker switch driven atcamshaft speed is also provided which, when closed, makes the Wild pingcounter ineffective for the duration of the normal flame in thecombustion chamber. The breaker is open for '80 crankshaft degreesbetween BTC (before top dead center) and 10 ATC (after top dead center).If a flame front induced early in the cycle by deposits reaches theionization gap during this open period, the counter registers a wildping regardless of the audible manifestations. During normal combustionwith ignition timing at TDC (top dead center) the flame front reachesthe ionization gap at 15 to 18 ATC during the period wherein the pointsare closed and no count is made. The actual test procedure consistsessentially of operating the test engine initially having a cleancombustion chamber under relatively mild cycling conditions for depositformation until an equilibrium with regard to deposit-inducedautoignition is reached. The effect of fuels treated in accordance withthis invention is determined by comparing the test results obtainedusing the fuel treated with an improved fluid of the present inventionwith those obtained using a fuel treated with a conventional antiknockmixture. Since the wild ping counter records the total number of wildpings which occur during the test procedures, a quantitative expressionfor the amount of deposit-induced autoignition is the number of wildpings per hour of operation. The eflec- --tiveness of .my improved fuelcomposition in virtually eliminating deposit-induced autoignition willbe apparent from the following specific examples.

Example 111 To gallons of a commercially available blend of straightrun, catalytically cracked, and polymer blending stocks Was added andthoroughly mixed 300 milliliters of tetraethyllead as an antiknock fluidcomprising tetra ethyllead, 0.5 theory of bromine as ethylene dibromide,and 1.0 theory of chlorine as ethylene dichloride. The resultinghomogeneous fuel composition was then utilized as the fuel in thepreviously designated single-cylinder laboratory test engine toformulate a base line of wild ping. It was found that there were 170wild pings per hour of engine operation.

Example IV An improved antiknock fluid composition of the presentinvention is prepared by adding 0.1 theory of phosphorus as the productobtained by reaction between P235, dodecyl amine and magnesium oxide tomilliliters of tetraethyllead as an antiknock fluid comprising tetraethyllead, 0.5 theory of bromine as ethylene dibromide, and 1.0 theoryof chlorine as ethylene dichloride. .A homogeneous fluid composition isobtained by intimately mixing the aforementioned components. The entirequantity of improved antiknock fluid composition so prepared is added to50 gallons of a commercially available blend of straight run,catalytically cracked, and polymer blending stocks. Upon mechanicallyagitating the resulting mixture a homogeneous fuel composition isprepared. The laboratory single-cylinder test engine as describedpreviously is then operated on this improved fuel composition whilecontemporaneously determining the rate of Wild pings as detected by thewild ping counter. It is found that the utilization of an improvedantiknock fuel of the present invention greatly'minimizes the rate ofwild pings per hour as contrasted with a conventional fuel which produce170 wild pings per hour.

vConsequently, an improved fuel composition of this invention results ina substantial reduction in this depositinduced engine phenomenon.

The foregoing specific examples are merely illustrative of thebeneficial effects produced by the improved organolead-containingcompositions of the present invention. It will be apparent that it ispreferred to utilize the adjuvants of this invention such as thereaction product between P235, ethyl aniline and sodium hydroxide; P457,ethanol amine and barium hydroxide; PSC1 p-phenylene diamine and zincoxide and the like in high octane quality fuel because of the fact thatmost of the deposit-induced problems exist on combustion of such fuels.

The superior effectiveness of the preferred embodiments of thisinvention, namely a metal-containing reaction product as definedhereinbefore in the diminution of deposit-induced engine problems isfurther unexpected when considering the prime constituents phosphorusand sulfur which are contained therein. On the one hand, both sulfur andphosphorus compounds have heretofore been judiciously avoided as much aspossible in fuel be cause of their notorious deleterious efiects,particularly in the realm of organolead antagonism and the like. 90 Inthe case of sulfur, for example, refiners have long been resorting tovarious means of removing sulfur compounds from hydrocarbons of thegasoline boiling range because of their recognized deleterious effectson antiknock activity, engine cleanliness, storage stability, and. thelike. However, the adjuvants of this invention possessing considerableproportions of phosphorus and sul fur do not bring about suchdeleterious effects. Furthermore, another surprising efiect has beennoted, namely, the fact that the presence of phosphorus-to-sulfurbondsproduces a greater eifectiveness regarding wild ping than thatexhibited by compounds possessing either phosphorus or sulfur, andlikewise, a mixture of phosphorusand sulfur-containing compounds. Thisfact is evidenced by the findings that the presence of added sulfur in aconventional leaded fuel not only has no beneficial effect on wild pingbut actually results in an increase in this phenomenon. By way ofexample, it was found that the addition of 5 theories of sulfur as amixture consisting of one theory of di-t-butyl disulfide, 2 theories ofdibutyl sulfide, and 2 theories of thiophene, a mixture representativeof the average sulfur constituents of petroleum hydrocarbon fuel, to aconventional gasoline containing 3 milliliters of tetraethyllead pergallon resulted in a wild ping rate of 93 Wild pings per hour. Incontrast, the same base fuel containing the same concentration oftetraethyllead produced 74 wild pings per hour. Thus, the incorporationof sulfur-containing compounds different from the sulfur-containingadjuvants utilized in this invention resulted in a wild ping rateamounting to per cent of the base line. That is to. say, the presence ofsulfur-containing compounds generally increases the rate of wild ping,whereas the presence of a considerable amount of sulfur when suitablybonded in accordance with the present invention results in a definiteimprovement in this deposit-induced phenomenon. In View of theforegoing, therefore, the apparent conclusion to be reached is that thechemical bonds between the two prime elements making up my adjuvants insome currently unexplainable manner produce enhanced effectiveness withregard to deposit-induced engine phenomena without resulting insecondary deleterious problems normally attributed to the presence ofeach of the elements when used separately or as mixtures of individualphosphorusand sulfur-containing compounds. 75

' As indicated, an additional important advantage obtained frompracticing this invention is the fact that my adjuvants have little orno antagonistic effect upon the antiknock agent used in the fuel. Inline with the enhanced effectiveness of my organolead adjuvants, thissurprising benefit regarding a minimum of organolead destructiveness isperhaps associated with the degree of oxidative stability inherent in mymetal-containing adjuvants. In other words, it is not inconceivable thatmy organolead adjuvants are capable of decomposing at the proper instantin the engine cycle so as to exhibit the beneficial effect regardingdeposit-induced engine problems while at the same time decomposing at atime during the engine cycle sufiiciently far removed from the point atwhich the organolead compound exerts its beneficial anti knock activity.

Because of their adaptability the adjuvants of the present invention canbe successfully utilized with any of the well-known organolead antiknockagents as indicated hereinbefore. Likewise, insofar as the halidescavengers are concerned, the metal-containing reaction products used asadjuvants in this invention can be employed in antiknock fluids andfuels containing such materials as ethylene dibromide, ethylenedichloride, mixed dibromotoluenes, trichlorobenzenes, and in generalsuch organic halide scavengers as those disclosed in U. S; 1,592,954;1,668,022; 2,364,921; 2,398,281; 2,479,900; 2,479,901; 2,479,902;2,479,903; and 2,496,983. Likewise, the adjuvants of this invention canbe used in conjunction with other well-known motor fuel adjuvants suchas antioxidants, organolead stabilizers, organic dyes, solubilizers,

and indeed with other catalytically active materials frequently employedin fuel.

.Having fully described the nature of' the present invention, the needtherefor, and the best mode devised for a carrying it out, it is notintended that this invention be limited except Within the spirit andscope of the appended claims.

I claim: 1. An antiknock additive for use in hydrocarbon fuels 7 of thegasoline boiling range, said additive comprising an organolead antiknockagent and a metallic derivative of a product obtained by reactionbetween (1') a phosphorus sulfide selected from the group consisting ofP285 and P487 and (2) an amine containing up to about 30 carbon atomsand at least one hydrogen atom directly attachedto a nitrogen atom, saidproduct being prepared by heating from about 0.5 to about 10 moles ofsaid amine per mole ;ofsaid sulfide to a temperature at which hydrogensultide is released, said metallic derivative being prepared by reactingsaid product at a temperature in the range of about to 350 F. with anamount of a metallic base i selected from the group consisting ofoxides, hydroxides,

.of the gasoline boiling range, said additive consisting essentially oftetraethyllead, a scavenging amount of organic halide material capableof reacting with the lead (luring combustion in a spark ignitioninternal combustion engine to form volatile lead halide, said materialcontaining only elements selected from the group consisting of bromine,chlorine, carbon, hydrogen, and oxygen; and a metallic derivative of aproduct obtained by reaction between (1) a phosphorus sulfide selectedfrom the group consisting of P285 and P487 and (2) an amine containingup to about 30 carbon atoms and at least one hydrogen atom directlyattachedto a nitrogen atom, said product being prepared by heating fromabout 0.5 to about 10 moles of said amine per mole of said sulfide to atemperature at which hydrogen sulfide is released, said metallicderivative being prepared by reacting said product at a temperature inthe range of about 180 to 350 F. with an amount of a metallic baseselected from the group consisting of oxides, hydroxides, and carbonatessufiicient to neutralize at least a part of the acidity of said product;said metallic derivative being present in said additive in amount suchthat the phosphorus-to-lead atom ratio is from about 0.02/3 to about1.6/3.

5. The additive of claim 4 further characterized in that said scavengingamount of organic halide material is about 0.5 theory of bromine as abromohydrocarbon compound capable of reacting with the lead duringcombustion in a spark ignition internal combustion engine to formvolatile lead bromide, and about 1.0 theory of chlorine as achlorohydrocarbon compound capable of reacting with the lead duringcombustion in a spark ignition internal combustion engine to formvolatile lead chloride.

6. Hydrocarbon fuel of the gasoline boiling range adapted for use asfuel for spark ignition internal combustion engines containing up toabout 6.34 grams of lead per gallon as an organolead antiknock agent,and a metallic derivative of a product obtained by reaction between (1)a phosphorus sulfide selected from the group consisting of P255 and P481and (2) an amine containing up to about 30 carbon atoms and at least onehydrogen atom directly attached to a nitrogen atom, said product beingprepared by heating from about 0.5 to about moles of said amine per moleof said sulfide to a temperature at which hydrogen sulfide is released,said metallic derivative being prepared by reacting said product at atemperature in the range of about to 350 F. with an amount of a metallicbase selected from the group consisting of oxides, hydroxides, andcarbonates sufiicient to neutralize at least a part of the acidity ofsaid product; said metallic derivative being present in said fuel inamount such that the phosphorus-to-lead atom ratio is from about 0.02/3to about 1.6/3.

7. The hydrocarbon fuel composition of claim 6 further characterized inthat it contains from about 0.53 to about 4.75 grams of lead per gallonas tetraethyllead, about 0.5 theory of bromine as a bromohydrocarboncompound capable of reacting with the lead during combustion in a sparkignition internal combustion engine to form volatile lead bromide, andabout 1.0 theory of chlorine as a chlorohydrocarbon compound capable ofreacting with the lead during combustion in a spark ignition internalcombustion engine to form volatile lead chloride.

8. The composition of claim 6 wherein the metal of said metallicderivative is selected from the group consisting of alkali and alkalineearth metals.

References Cited in the file of this patent UNITED STATES PATENTS2,378,793 Rudel June 19, 1945 2,405,560 Campbell Aug. 13, 1946 2,534,217Bartleson Dec. 19, 1950 FOREIGN PATENTS 683,405 Great Britain Nov. 26,1952

6. HYDROCARBON FUEL OF THE GASOLINE BOILING RANGE ADAPTED FOR USE ASFUEL FOR SPARK IGNITION INTERNAL COMBUSTION ENGINES CONTAINING UP TOABOUT 6.34 GRAMS OF LEAD PER GALLON AS AN ORGANOLEAD ANTIKNOCK AGENT,AND A METALLIC DERIVATIVE OF A PRODUCT OBTAINED BY REACTION BETWEEN (1)A PHOSPHORUS SULFIDE SELECTED FROM THE GROUP CONSISTING OF P2S5 AND P4S7AND (2) AN AMINE CONTAINING UP TO ABOUT 30 CARBON ATOMS AND AT LEAST ONEHYDROGEN ATOM DIRECTLY ATTACHED TO A NITROGEN ATOM, SAID PRODUCT BEINGPREPARED BY HEATING FROM ABOUT 0.5 TO ABOUT 10 MOLES OF SAID AMINE PERMOLE OF SAID SULFIDE TO A TEMPERATURE AT WHICH HYDROGEN SULFIDE ISRELEASED, SAID METALLIC DERIVATIVE BEING PREPARED BY REACTING SAIDPRODUCT AT A TEMPERATURE IN THE RANGE OF ABOUT 180 TO 350*F. WITH ANAMOUNT OF A METALLIC BASE SELECTED FROM THE GROUP CONSISTING OF OXIDES,HYDROXIDES, AND CARBONATES SUFFICIENT TO NEUTRALIZE AT LEAST A PART OFTHE ACIDITY OF SAID PRODUCT; SAID METALLIC DERIVATIVE BEING PRESENT INSAID FUEL IN AMOUNT SUCH THAT THE PHOSPHORUS-TO-LEAD ATOM RATIO IS FROMABOUT 0.02/3. ABOUT 1.6/3.